I have ANP on my iphone but never use it. From the ouset I found it difficult to use whereas Skydemon is just simplicity itself. I'm not a computer geek which probably makes me an ideal judge. Skydemon is one of the best bits of software I've ever seen. Download it and use it, SIMPLES!
I have also looked at PocketFMS as my EFIS manufacturer is going to switch to it from Jeppesen for map data. I am delighted that they are doing this as Jepp is crap and PocketFMS looks good but would be ecstatic if they were moving to Skydemon!